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Volume Graphics and the Internet

Volume Graphics and the Internet

Ken Brodlie and Jason WoodSchool of Computer Studies

University of Leeds

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InternetInternet

The Internet brings connectivity Connectivity means…

– humans can collaborate

– systems can collaborate

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Why Collaborative Visualization?

Why Collaborative Visualization?

Visualization IS a collaborative activity!

Scientific research is carried out in multi-disciplinary teams– each person brings individual skills– teams may be geographically distributed

Influence of the Internet and Web– collaborative culture

BUT existing visualization systems:– single user model and pre-Web

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How Can We Collaborate?How Can We Collaborate?

General application sharing– one host acts as master, broadcasts

screen display to other participants– collaboration at the operating system

level– SharedX, MS NetMeeting– high bandwidth requirement

Collaborative visualization systems– use knowledge of application to get a

better solution

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Collaborative Visualization - Outline of First Part of

Talk

Collaborative Visualization - Outline of First Part of

Talk

Influences– other work on collaborative

visualization Concept

– linked dataflow Realisation

– IRIS Explorer COVISA toolkit Application

– collaboration in volume visualization

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Tempus Fugit - Sharing Geometry

Tempus Fugit - Sharing Geometry

CFD visualization system developed by Michael Gerald-Yamasaki at NASA Ames - Eurographics 93SimulationVisualization

supercomputer

Geometry list

workstation

Rendering

Rendering

workstation

Interview

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ONERA - Sharing ControlONERA - Sharing Control

In the EU PAGEIN project, Michel Grave at ONERA developed a ‘shared interface’ approach

Parameters to be shared extracted into a shared interface aboveabove the visualization system

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CSpray - Collaboration Issues

CSpray - Collaboration Issues

Extension of Alex Pang’s Spray rendering

Particles fired into data with specific objective - eg locate isosurface

In CSpray, each person has a spray can

Careful study of issues– floor control– privacy– audit trail

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COVISA Research Objective

COVISA Research Objective

Our aim was to evolve a collaborative extension of Modular Visualization Environments– IRIS Explorer, AVS, IBM Data Explorer,

Khoros– usability:usability: keep same metaphor– sharing:sharing: share data and control with

other participants– flexibility:flexibility: programprogram the collaboration

to allow network efficiency, privacy, join-at-any-time

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We have this...We have this...

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… we want this… we want this

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Back to the Visualization Reference Model

Back to the Visualization Reference Model

To design a collaborative visualization system, we return to the underlying Haber-McNabb reference model - and think how to extend it:

FILTER MAP RENDERINPUTDATA

simulation

measurement

geometry(surface/volume)

imagefiltereddata

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Collaborative Dataflow Model

Collaborative Dataflow Model

FILTER MAP RENDERINPUTDATA

FILTER MAP RENDERINPUTDATA

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Collaborative Dataflow Modules

Collaborative Dataflow Modules

FILTER MAP RENDERINPUTDATA

ADVISOR

Internet

FILTER MAP RENDERINPUTDATA

SHARE PARAM

SHARE PARAM

SHARE DATA

SHARE DATA

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Use My Network...Use My Network...

ADVISOR

FILTER MAP RENDERINPUTDATA

Internet

FILTER MAP RENDERINPUTDATA

senior scientist

junior scientist

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See What I Can See...See What I Can See...

FILTER MAP RENDERINPUTDATA

ADVISOR

Internet

FILTER MAP RENDERINPUTDATA

SHARE PARAM

SHARE PARAM

senior scientist

junior scientist

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See What You Can See...See What You Can See...

ADVISOR

FILTER MAP RENDERINPUTDATA

Internet

RENDER

SHARE DATA

SHARE DATA

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Do Your Own Thing...Do Your Own Thing...

ADVISOR

FILTER MAP RENDERINPUTDATA

Internet

MAP RENDER

SHARE DATA

SHARE DATA

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Can I Use Your Expertise?Can I Use Your Expertise?

FILTER RENDERINPUTDATA

ADVISOR

Internet

SHARE DATA

MAP

SHARE DATA SHARE DATA

SHARE DATA

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IRIS Explorer COVISA Toolkit

IRIS Explorer COVISA Toolkit

This research is now available as the COVISA add-in to IRIS Explorer

Advisor, ShareParam, ShareData modules...

...wired in to networks exactly like any other

See IRIS Explorer Centre Web Site:– http://www.scs.leeds.ac.uk/iecoe

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COVISA ArchitectureCOVISA Architecture

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Starting a SessionStarting a Session

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New ModulesNew Modules

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Advisor ModuleAdvisor Module

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Collaborative ModulesCollaborative Modules

Modules can be written as directly collaborative – for example, MSharePointer

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Collaborative ApplicationsCollaborative Applications

End-user applications can be built as a layer on top of a dataflow network– selected parameters exposed to

users in a simple interface– collaboration can be included in

these

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ApplicationApplication

Video will show application to volume visualization

Radiologist studying abdominal aortic aneurysm..

… collaborates with a medical physicist with segmentation skills

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The Story Begins With...The Story Begins With...

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Web-based VisualizationWeb-based Visualization

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Visualization and the World Wide Web

Visualization and the World Wide Web

Early use for descriptivedescriptive visualization– visualize using conventional software

such as MVEs– publish as an image, or as 3D VRML

model Now used also for analytical or analytical or

exploratory visualizationexploratory visualization– visualization process executed as a Web-

based application Web-based visualization has become

an established branch of discipline

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How Did It Start?How Did It Start?

Pioneering work by Ang et al 1994– medical volume visualization system VIS

used as a client-sideclient-side application linked to Mosaic browser

– invoked on receipt of MIME-type ‘hdf/volume’

Server-side example from Wood 1995– air quality visualization service– IRIS Explorer on serverserver, returning VRML

Now many styles of web-based visualization– some client-basedclient-based, some server-basedserver-based

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Client-based SystemsClient-based Systems

Action is at the client

Three flavours according to what is sent from the Web server:

– raw data– script to drive

software– software

Webserver

Browser

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Sending data - Vis5DSending data - Vis5D

Vis5D: for meteorological visualization, from Hibbard at Wisconsin

Configured as helper application, invoked on receipt of MIME-type ‘application/vis5d’

Daily weather forecasts

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Sending a Script : Client-Explorer

Sending a Script : Client-Explorer

Client-based system with IRIS Explorer developed by Alan Yeo and Jason Wood at Leeds

Set of instructions downloaded from server to ‘program’ IRIS Explorer on the client

Instruction file invokes application which drives IE

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Sending Software : VizWizSending Software : VizWiz

VizWiz is Java applet for volume visualization, from Michaels & Bailey at SDSC

Data is a problem: must be uploaded from client to server to work around Java security issues

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Server-based SystemsServer-based Systems

Action is at the server

Three flavours according to what is sent from the server:

– 3D graphics– 3D graphics plus

software– images / video

Webserver

Browser

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Sending VRML : Air Quality Visualization

Service

Sending VRML : Air Quality Visualization

Service

Air quality web-based visualization system with IRIS Explorer on server, developed by Jason Wood

User completes form saying what data, and what technique

CGI script invokes IRIS Explorer

VRML returned

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Sending VRML and Java: Isosurfacing

Sending VRML and Java: Isosurfacing

Engel and colleagues at Erlangen have implemented their progressive isosurface algorithm as a web-based system

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Sending VRML and Java:Volume Rendering

Sending VRML and Java:Volume Rendering

Texture-based volume rendering can be delivered as VRML

This VRML volume rendering developed by Nigel John and colleagues at SGI Biomedical

Java applet provides interaction

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Sending Images/Video: Volume Render

Sending Images/Video: Volume Render

Rather than render on the client, it is possible to render on a server and ship the images to the client…

… this approach has been used by Stredney et al at Ohio for remote volume rendering

Client uploads data to server (with 3D texture hardware)

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ReviewReview

Client-based– high interactivity– needs software

availability at client, plus skill to use it

– needs compute power at client… but this is dedicated

Server-based– low degree of

control– software provided

by server– compute power

provided by server … but shared between many

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Extending to Collaborative Web-based Visualization

Extending to Collaborative Web-based Visualization

Both client and server based systems can be extended to collaborative style of working - although surprisingly little work has been done in this area

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Client-based SystemsClient-based Systems

FASTexpeditions can run in a pilot-passenger mode

ClientExplorer can be extended to incorporate the COVISA shared modules

VisAD has been used in a collaborative setting, with NCSA Habanero

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Server-based SystemsServer-based Systems

Air quality visualization service (IRIS Explorer on server) has been extended to support asynchronous collaboration

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Collaborative Web-based Visualization

Collaborative Web-based Visualization

Future direction could be combination of synchronous collaboration provided by the extensions of MVEs described earlier

…and the asynchronous collaboration for which the Web is well suited, providing a sustainable environment for collaboration

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BaseSoftware

InputData

Design

Setup

Script

Reference Model - The Processes

Reference Model - The Processes

RenderC

S

C

S

C

C

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Client-based SystemsClient-based Systems

Design executed on client-side

BaseSoftware

Data

SetUp

Design

Script

RenderC

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Vis5DVis5D

All components except the data are resident on the client, and executed on the client

BaseSoftware

Data

SetUp

Design

Script

Render

C

S

C

C C

C

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FAST ExpeditionFAST Expedition

FAST: CFD visualization system from NASA Ames

Setup and script can be downloaded from server - so a guided tour is possible

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FAST ExpeditionFAST Expedition

Distinguished from Vis5D because system ‘SetUp’ and ‘Script’ driven from server

Client can take over the ‘driving’ - hence Script is Client or Server based

BaseSoftware

Data

SetUp

Design

Script

Render

C

S

S

C C

CS

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Client-ExplorerClient-Explorer

Distinctive in that ‘SetUp’ and ‘Script’ can be either client or server driven

Potential application for

– education– bureau services

BaseSoftware

Data

SetUp

Design

Script

Render

C

S

CS

C C

CS

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Java Applet ApproachJava Applet Approach

Key feature is base software on server, but execution on client Base

Software

Data

SetUp

Design

Script

Render

S

S

S

C C

C

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VisADVisAD

VisAD is novel Java based system from Hibbard at Wisconsin

Idea of linked objects - data objects linked to user interface objects etc

Objects are Java classes that can reside at any URL

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VisADVisAD

Software can be resident either on client, or a remote server

BaseSoftware

Data

SetUp

Design

Script

Render

CS

C

C

C C

C

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Server-based VRML Approach

Server-based VRML Approach

Server-side execution, with client-side rendering

Setup determined by client

BaseSoftware

Data

SetUp

Design

Script

Render

S

S

C

S C

S